• 센서학회지
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• 제20권2호
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• pp.124-130
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• 2011

In this study, in order to evaluate the yield of bubble by ultrasonic cavitation in HIFU sonication, the bubble image analysis was performed. The changing phenomenon of cavitation effect according to the sonication condition was discussed by analyzing the bubble image. Especially the appearance of bubble cloud, the size of micro-bubble, and the yield of bubble were considered. The 500 KHz and 1.1 MHz concave type ultrasonic transducers were used for HIFU sonication. Computer controlled digital camera was used to obtain the bubble image, and the binary image processing(binarization coefficient : 0.15) was performed to analyze them. In results of 500 KHz and 1.1 MHz transducer, the area of bubble cloud was increased in proportion to the rise in sonication intensity($R^2$ : 0.7031 and 0.811). The mean size of single microbubble was measured as 98.18 um in 500 KHz sonication, and 63.38 um in 1.1 MHz sonication. In addition, the amount of produced bubble was increased in proportion to sonication intensity. Through the result of this study and further study for variable image processing method, the quantitative evaluation of ultrasonic cavitation effects in HIFU operation could be possible with the linearity associated with the sonication conditions.

• 응용통계연구
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• 제28권2호
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• pp.201-210
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• 2015

생명과학 또는 의학 연구에서는 반복 측정된 변수들 간의 상관 관계를 보고자 하는 경우가 발생한다. 반복 측정된 것을 고려하지 않으면 상관관계를 과소 추정하는 경향이 나타나므로 이를 고려해야 하며, 선형혼합모형의 분산-공분산 행렬을 이용하여 상관관계를 추정할 수 있다. 본 연구에서는 변수들의 반복 측정이 동시에 된 경우와 그렇지 않은 경우로 나누어 혼합모형을 이용한 상관계수의 추정방법을 소개한다. 고속 음향 복사력 임펄스 영상(acoustic radiation force impulse imaging; ARFI)으로 간과 비장에서 각각 세 번씩 전단파 속도를 반복 측정하고 복부 초음파 검사로 비장 길이를 측정한 자료에서 전단파 속도와 비장 길이 간의 상관 관계를 분석하기 위해 본 논문에서 소개한 방법들을 적용하였고 SAS의 PROC MIXED를 이용하는 방법을 제시하였다.

• 생약학회지
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• 제43권1호
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• pp.66-71
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• 2012

Cirsium japonicum var. ussuriense is often used in treatment of human disease such as hemorrhage, blood congestion and inflammation. This study was accomplished to evaluate the antioxidant properties of the leaf (CLE) and flower (CFE) extracts of C. japonicum var. ussuriense to protect normal human red blood cells (RBC) and plasma samples against oxidative damage in vitro. CLE and CFE were prepared by extracting with hot water. In red blood cells and plasma, oxidative hemolysis and lipid peroxidation induced by the aqueous peroxyl radical generator [2,2'-azobis (2-amidinopropane) dihydrochloride, AAPH] were significantly suppressed by CLE or CFE in a dose-dependent manner at the same time. CLE and CFE also prevented the depletion of cytosolic antioxidant glutathione (GSH) in RBC. These results suggest that the leaves and flowers of C. japonicum var. ussuriense may have the antioxidant properties.

• Biomolecules & Therapeutics
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• 제11권4호
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• pp.205-213
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• 2003

Various angiogenesis inhibitors target vascular endothelial cells and block tumor angiogenesis. Angiostatin is a specific endogenous angiogenesis inhibitor in clinical trials, which contains only the first four triple loop structures, known as kringle domains. Its generated by proteolytic cleavage of its parent molecule plasminogen, which itself does not exhibit antiangiogenic activity. Kringle domains from prothrombin, apolipoprotein, hepatocyte growth factor, urokinase and tissue-type plasminogen activator also elicit anti-angiogenic or antitumor activities in several model systems, albeit low amino acid sequence identity between angiostatin and each individual kringle. However, the differential effects of each kringle domain on endothelial cell proliferation, and migration observed in these kringle domains, suggest that the amino acid sequence of the primary structure is still important although kringle architecture is essential for anti-mlgiogenic activity. If it is further studied as to how amino acid sequence and kringle architecture contributes in anti-angiogenic activity, with studies on underlying mechanisms of anti-angiogenesis by kringle-based angiogenesis inhibitors, it will provide basis for the development of new potent anti-angiogenesis inhibitors and improvement of the efficacy of angiogenesis inhibitors.

• 방사선산업학회지
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• 제5권3호
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• pp.203-210
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• 2011

To evaluate the ability of Bamboo (Phyllostachys nigra var. henenis Strapf) leaf extract (BL) to protect the skin from photodamage, the gross and microscopic changes in the skin of hairless mice and BL-treated mice exposed chronically to ultraviolet (UV) were examined. The skin of the UV-irradiated mice showed characteristic signs of photoaging, such as deep wrinkles across the back, increased epidermal thickeness, numerous cell infiltration, and many enlarged keratinizing cysts. BL-treated mice showed a significantly decreased wrinkling score and lack of proliferation of cysts. By the 22nd week, 88.9% (i.p. with saline) or 60.0% (topical administration with cream base) of the UV-irradiated mice developed at least one tumor. BL delayed tumor onset significantly. BL (i.p.) was also effective in reducing the occurrence of UV radiation-induced skin tumors and reduced the number of tumors per mouse. After 22 weeks of treatment, 37.5% (i.p.) of the mice treated with BL were tumor-free. Tumor multiplicity was reduced by 81.2% (i.p.) in the BL treated groups. It is noted that skin that is chronically exposed to UV is subject to photoaging and photocarcinogenesis and regular use of BL would prevent these photodamaging effects of UV.

• 방사선산업학회지
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• 제10권4호
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• pp.231-242
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• 2016

This study was conducted to evaluate the synergistic protective effects of mixtures of corn silk, perilla leaf and grape stem extract (CPG mixture) against UVB-induced skin damage and compound 48/80-induced pruritus in mice. The results showed that treatment with CPG mixture exhibited much stronger suppressive effect on erythema and melanin index as well as melanin formation than treatment with ascorbic acid (AA) in UVB-irradiated mice. Moreover, the treatment with CPG mixture showed ameliorative effect on immune cell infiltration and collagen fiber destruction in UV-irradiated mice. The treatment with CPG mixture inhibited glutathione (GSH) depletion, lipid peroxidation and production of pro-inflammatory cytokines in UVB-irradiated mice. Furthermore, the treatment with CPG mixture inhibited compound 48/80-induced scratching behavior and histological changes in mice. Taken together, these results indicated that CPG mixture has potentials as functional and therapeutic materials against skin damage and itch-related skin diseases.

• 방사선산업학회지
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• 제4권3호
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• pp.239-246
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• 2010

The aim of this study is selection of the male-sterile plant for inhibiting transgene flow through gamma-irradiation ($^{60}Co$) at the pollination and fertilization cycle of herbicide-tolerant genetically modified (GM) zoysiagrass (Zoysia japonica Steud.). High frequencies of plant mutations were obtained about 18% from $M_1$ generation at the doses (10 to 50 Gy). We also found that some $M_1$ plants showed male-sterile plants using de-husked seeds and comparison of stainable pollen using $KI-I_2$ solution. Besides the effects of irradiation on pollination and fertilization cycle, various other mutations like dwarf, cold tolerance, increasing grains and mass were observed. Four of dwarfism plants were selected through comparison of morphological characteristic between control and mutants during 4 years. These results demonstrated that the gamma-irradiation on pollination and fertilization cycle is very effective to induce the various mutations, and the male-sterile mutants are useful for controlling transgene flow and developing of high quality turfgasses.

• Nuclear Engineering and Technology
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• 제40권4호
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• pp.255-268
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• 2008

The greater demand for electricity and the available capacity within safety margins in some operating NPPs are prompting nuclear utilities to request license modification to enable operation at a higher power level, beyond their original license provisions. Such plant modifications require an in-depth safety analysis to evaluate the possible safety impact. The analysis must consider the thermo hydraulic, radiological and structural aspects, and the plant behavior, while taking into account the capability of the structures, systems and components, and the reactor protection and safeguard systems set points. The purpose of this paper is to introduce international experiences and approaches for implementation of power uprates related to the reactor thermal power of nuclear power plants. The paper is intended to give the reader a general overview of the major processes, work products, issues, challenges, events, and experiences in the power uprates program. The process of increasing the licensed power level of a nuclear power plants is called a power uprate. One way of increasing the thermal output from a reactor is to increase the amount of fissile material in use. It is also possible to increase the core power by increasing the performance of the high power bundles. Safety margins can be maintained by either using fuels with a higher performance, or through the use of improved methods of analysis to demonstrate that the required margins are retained even at the higher power levels. The paper will review all types of power uprates, from small to large, and across various reactor types, including light and heavy water, pressurized, and boiling water reactors. Generally, however, the content of the report focuses on power uprates of the stretch and extended type. The International Atomic Energy Agency (IAEA) is developing a technical guideline on power uprates and side effects of power uprates in nuclear power plants.

• 대한임상독성학회지
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• 제8권2호
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• pp.113-121
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• 2010

Purpose: Drug-induced non-cardiogenic pulmonary edema has been reported on in a drug case series. For most of the agents that cause pulmonary edema, the pathogenic mechanisms that are responsible for the pulmonary edema remain unknown. We report here on the cases of suspected drug-induced pulmonary edema and we analyze the clinical characteristics. Methods: We reviewed the medical records of 1,345 patients who had drug adverse effects and drug poisoning from January 2005 to July 2010, and 480 of these patients were admitted to the EM Department. Among them, 17 patients developed abnormal chest radiological findings and they were analyzed for any clinical characteristics, the initial symptoms, securing the airway and the clinical results. Results: Seventeen patients out of 480 (3.54%) developed drug-induced abnormal chest radiographic pulmonary edema; they displayed initial symptoms that included mental change (41.2%), dyspnea (17.6%), vomiting (11.8%), etc, and some displayed no symptoms at all (11.8%). Only 3 patients out of the 11 who died or had severe pulmonary edema were able to obtain an advanced airway prior to their arrival to the EM Department. Clinical recovery was generally rapid and this was mostly completed within 6 hours. The mortality rate was 11.8% (2 of 17 patients), and the causative drugs were found to be propofol (35.3%, 6 of 17 patients), multiple drugs (41.2% or 7 out of 17) and one patient each with ephedrine, ethylene glycol, doxylamine and an unknown drug, respectively. Conclusion: Drug-induced pulmonary edema and deaths are not uncommon, and recovery is typically rapid with few long-term sequelae when drug administration is discontinued. Oxygen therapy and securing the airway must be performed during transportation for patients with pulmonary edema.

• 한국방사선학회논문지
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• 제15권2호
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• pp.181-189
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• 2021

본 연구는 방사선치료 시 사용하는 고정용구 인 열가소성 플라스틱 마스크를 3D 프린트로 제작하기 위한 선행 연구로써 열가소성 플라스틱을 대체할 수 있는 필라멘트 재질을 분석하고자 진행하였다. 시중에 상용화되어 있는 필라멘트 재질 중 열가소성 플라스틱 마스크와 특성이 유사한 재질을 선택하여 방사선량을 비교 분석하였다. 실험은 몬테칼로 시뮬레이션을 이용하였으며, 마스크가 두부를 고정한 형태를 ICRU구를 대상으로 모사하고 열가소성 플라스틱 재질과 필라멘트 재질을 적용하여 피부 Hp(0.07), 수정체 Hp(3), 전신 Hp(10) 지점에서 광자 플루언스를 계산하였다. 그 결과 열가소성 플라스틱 재질을 기준으로 상대적인 선량을 보면 차이가 4% 이내로 근사한 값을 나타내었으며, 가장 유사한 선량을 보인 재질은 PA-nylon으로 나타났다. 적절한 필라멘트 재질 선택에 있어서 경제성, 방사선 영향 등 다양한 조건을 종합적으로 고려하여 선택해야 할 것이며, 본 연구 결과를 기초적인 자료로써 활용할 수 있을 것으로 생각된다.